In communication networks, different schemes have been used to improve communication between a base station (BS) and subscriber station (SS) across the network. For example, some networks employ a single transmit antenna and single receive antenna at the BS and subscriber station SS. These systems may improve communication, i.e., increase SINR, by employing adaptive coding/modulation schemes, where the signal modulation scheme is adjusted to effectuate an increase in SINR. Other networks employ different antenna array modes, i.e., modes of communication, between a BS and a SS where each of the BS and SS have multiple antennas. Examples of these multiple antenna array communication modes include Space-Time Block Code (STBC), Multiple-Input Multiple-Output (MIMO), Space Division Multiple Access (SDMA), and beam forming (BF) techniques. Each of these multiple antenna array communication modes is advantageously used under certain conditions, but are of only limited usefulness under other conditions. For example, SDMA schemes provide good coverage and efficient use of available spectrum, but are limited to effective use only with non-moving or slow-moving SSs. An STBC scheme is best used for fast-moving, dynamic SSs, but provides less efficient use of available spectrum. On the other hand, a Beam Forming (BF) scheme is most effective for communications involving subscribers at or near cell boundaries as it can be used to increase signal strength and reduce interference from other cells.
More often than not, simply employing a single mode of communication for communication is not practical because any given mode is not versatile enough to be useful across a sufficiently wide range of conditions. As such, schemes have been employed where the network switches from one mode of communication to another to accommodate the changing conditions. Nevertheless, these schemes are somewhat limited in that they only provide switching between, at best, two modes. Also, such systems are limited because they typically consider only SS position when deciding to switch between communication modes. While some of these systems are touted as being operable to switch between multiple antenna modes; at best, these systems switch between only two modes and are limited to point-to-point communication. Further, these systems do not optimize communication mode selection point-to-multiple-point in a multi-cell context.
By way of example, suppose a user is operating in a LAN type environment. In all likelihood, the user will have only one available communication scheme, e.g., MIMO, across the network. Another communication mode, e.g., BF will not be available to that user because it has not been implemented in such an environment. Of course, BF has been implemented in such networks, typically in a proprietary form in the CDMA context, and the like. However, in no case has MIMO, for example, been additionally implemented in the same network. Accordingly, a user of the network has been forced to settle for one mode of communication or another.